The present invention relates to scanning probe microscopy, and more particularly to using atomic force microscopy (AFM) to produce an image true profile representative of a structure.
AFM is a metrology tool that is useful for measuring and calibrating surface features of structures having dimensions in the nanometer and micrometer range. AFM may be used to scan structures made of any material to produce high resolution two-dimensional profile and three-dimensional images of the structure. AFM is an important tool for measuring dimensions of semiconductor devices, magnetic recording devices, and microelectromechanical system (MEMS) devices.
However, a significant drawback of utilizing AFM with a tube scanner for measuring dimensions is that the images generated are susceptible to a large Z direction run out error (Zrr). The large Zrr causes an artificial system “bowing” or “curving” effect in the surface profile of the device being scanned. Over large scan areas Zrr becomes greater, and therefore, can lead to inaccurate measurements of the device being scanned. Thus, for a device requiring a large scan size, for example the entire slider used in a magnetic disc drive, Zrr can prevent performing true shape measurement using AFM.